It is well known that the escalator, the moving walk and the like comprise heads, and elements of the head, including comb plate carriers, a comb plate, balustrade brackets, skirt fastening brackets, a handrail belt inlet bracket and etc., are either mounted separately on a truss of the escalator or moving walk and adjusted individually, or mounted on the truss of the escalator or moving walk after being pre-assembled as a sub-assembly. In addition, the existing escalator and moving walk are usually provided with a monitoring device for monitoring the position of the comb plate. During the operation of the escalator, the monitoring device is used to monitor backward displacement of the comb plate due to abnormal situations such as the collision between steps and the comb plate or objects being stuck between the steps and the comb plate, the backward displacement of the comb plate will actuate a safety switch so as to stop the operation of the escalator.
U.S. Pat. No. 7,234,583B2 has disclosed a comb plate-comb plate carrier sub-assembly for an escalator or a moving walk, and a monitoring device for monitoring the position of the comb plate.
The comb plate-comb plate carrier sub-assembly disclosed in the reference document is pre-assembled beforehand. In order to hold the relative positions of components, especially the comb plate and the comb plate carriers, during transportation and assembling, the comb plate itself is used as a positioning and connecting element, and is securely fastened to the comb plate carriers on both sides by bolts, so that the comb plate and the comb plate carriers form a rigid unit. After the sub-assembly is mounted onto the truss, the bolts as fastening elements are removed so as to allow the horizontal displacement of the comb plate. However, during installation, it requires additional tools to lift and mount the comb plate-comb plate carrier sub-assembly on the truss, leading to inconvenient, time-consuming and costly mounting.
The monitoring device disclosed in the reference document can only monitor the backward displacement of the comb plate due to abnormal situations during the operation of the escalator, but can not monitor the upward displacement of the comb plate due to abnormalities during the operation of the escalator. However, there exists such a situation that the comb plate is displaced upward due to abnormal situations such as the collision between steps and the comb plate or objects being stuck between the steps and the comb plate during the operation of the escalator. So the monitoring device disclosed in the reference document can not fully monitor the abnormal situations of the escalator.
In view of the above problems of the traditional comb plate-comb plate carrier assembly and the monitoring device for monitoring the position of the comb plate, there are requirements for further improving the comb plate-comb plate carrier assembly and the monitoring device.